Prius as Generator When Power Is Out

I'm in post-hurricane Houston and am interested in using one or more of my 3 (yes, 3) Priuses as an emergency generator for the next freezepocalypse or baby hurricane that comes my way. I like that I already own 3 potential generators in my driveway so would not have to spend several hundred dollars or more on a gas- or solar-powered generator. I also really like that the car is quieter than a generator, the exhaust is less, cleaner, and will be further away from the house. It seems reasonable that the car must be much more fuel efficient than a gas generator since gas will only be used intermittently to power up the HV battery. The only downside I can see is that I can't get as much power from the car as I can from a traditional generator (more on that below) but that's fine with me.

Reading fellow Houstonians post-hurricane comments, I can see that folks spent a lot on gas (gasoline and LP gas) and also used a lot of gasoline/LP gas which was hard to find for a few days, defeating the purpose of having a stand-alone generator. I don't have the option of a an installed gas line.

According to very many post-storm reports, gas generators seem to use about one-half to one full gallon of gas per hour and also require frequent maintenance and rest periods that I'm not terribly interested in doing. I don't know what a Prius would use in gasoline just sitting in "Ready" state, but it certainly would be less than what a gasoline-powered generator would use.

I've gathered from reviewing possibly every post or video available in the internet that I should not use a larger than 1000 watt (pure sine wave if using for any delicate electronics) inverter on the 12v battery to stay comfortably below maxing out the potential wattage available via the car.** I have seen 2 YT videos and one comment on here from folks who have used a 2000 watt inverter, but I think they overbought and I'd also like to stay low to not put any of my 3 cars in any danger since all 3 are also daily use vehicles.

So is the 1000 watt inverter the best choice for safety in your (anyone who has considered, is knowledgeable about, or has done this) opinion? I think so. Do you see any flaws in my reasoning here?

I also understand I should stay 20% below the maximum of 1000 watts available using the inverter so I was thinking that I could get a comfortable 800 watts per car. 800 watts would give me a great deal of comfort. I've determined that my fridge uses 379 watts. Caution says I should allow twice that for surges- or when the fridge needs to power up- so I calculated to allow the fridge 758 watts max. I'm thinking I would use one car and one 1000 watt inverter as a stand-alone for the fridge only. Spending about $200 dollars on an inverter, connecting cables, and a heavy duty power cord, and not losing a couple of hundred dollars worth of food makes this seem like a good investment. Do you (anyone who has considered, is knowledgeable about, or has done this) have an opinion on this? Any reason why the cables from the 12v battery/ground to the inverter should be heavy duty cables?

I was thinking I could disconnect the fridge from time-to-time to power other kitchen stuff except that other kitchen items use a surprisingly large amount of power. For example, the coffee pot says it needs 1550 watts. The microwave says it needs 1150 watts. The tea kettle wants 1000 watts. At these numbers, I'm not sure I can actually use even the tera kettle if I adhere to my previous cautious plans of 800 watts max. I guess I'm wondering if I'm being overly cautious or if I should just plan on some other method(s) of food prep.

I still have two other cars and could use one or two of them to run stuff like fans, lights, and even the router and household computers, since none of those items are watt-hogs. This would make life much less boring.

A final question- most inverters allow for two extension cords. I presume this means, using my cautious math, that I can only plan on about 400 watts per cord (or 500/300, 0r 200,600, etc.) Is this correct?

I guess I'd like opinions and thoughts on these plans and also opinions and thoughts on if I'm being too conservative on my planned usage of 800 watts per car.



**"The Prius (all generations, as far as I'm aware) has a 100 amp (fuse limitation) on the DC to DC converter that charges the 12V battery.

100 amps x 12 volts = 1200 watts absolute maximum.

The car's electronics require some portion of that maximum 1200 available watts while in READY mode.

A 1000 watt continuous inverter is the absolute largest one recommended, if drawing power through the 12V battery."
Credit to SweetBearCub here:

 

Thank you so much! Very helpful!

 

I just don't really want to spend a bunch of money on generators when I already have 3 in the driveway.

I would indeed have a generator running for days and "standing in the heat" since I'm on the south Texas coast. It's regularly 95 to 100 degrees daily right now and it won't start to cool off here until mid to late October. Thanks for the advice on building a shed over a generator. Most folks here have not been doing that.

The maintenance I want to avoid is adding gas every 6 or so hours, changing the oil every 100 hours while in use, allowing the generator to rest daily, the regular, scheduled maintenance when a generator is not in use, and the storing oil and gasoline.

Obtaining gasoline and LP gas was a problem for many folks using generators during our most recent Cat I since most businesses were closed due to lack of power. Hurricane Beryl landed here July 8th as a Cat I hurricane. A Cat 1 should not have shut down the city the way it did. The 4th largest city in the nation shut down for days. It's ten days later now and too many Houstonians are still without power.

But even $2,000 - $3,000, not to mention $10,000, is out of budget for me right now which is why I'm interested in using the cars I already own. Some generators cost less of course, but why spend even several hundred dollars on a small, high-maintenance one (low wattage, small gas tank, mostly) when I already own something I can use that would give me the same results for a couple of hundred dollars or less per car?

I do appreciate your comments though! It gives me stuff to think about.

TY!

 

Thanks so much! I had read that post of yours already and got a lot of useful information from it- especially on the Instant Pot. That sent me to the kitchen and other places to look at the wattage needs of the appliances I already have. The numbers were surprising!

Salton 6 Cup Rice Cooker- 300 Watts
Crock Pot- 250 Watts
Fancy New Ninja Coffee Pot- 1550 Watts
Old 5-Cup Coffee Pot- 700 Watts
Aroma Tea Kettle- 1500 Watts
Black and Decker Toaster Oven- 1150 Watts
GE Microwave- 950 Watts
Electric oven- 2000 Watts best guess (very, very old)
Electric cooktop- unknown (also very, very old)

We had used our fireplace and camping gear to cook during the 2021 freezepocalypse we had a while back because it was just too cold to use the camp stove outside.


Small, 9” round black desk fan- 75 Watts
Heavy Duty Shop Fan- 100 Watts (best guess)
20" Box Fan- 75 Watts
Blue Gooseneck Table Lamp 50 Watts- halogen bulb
LED Gooseneck Table Lamp with magnifier -5 Watts
6 Foot Floor Lamp- bulb dependent
Jim’s Shop/Box fan- may use 100 Watts- best guess

Thanks so much!

 

Hmm, I'm not sure where I got that microwave number now. Regard it with suspicion!

 

All done!

How I Prepared My 2012 Prius Hybrid For Use As An Emergency Generator To Run My Refrigerator In A Power Outage. (Long)

 

All very good ideas- thank you! Adding an additional fan did cross my mind and running a more robust test is a very good idea.

I probably added too much detail in my report but the people who bother to do this (like me) seem to want and need a lot of detail.

I'm still puzzled by the low Wattage the refrigerator required over what I expected. I added a known quantity- the 40 Watt test lamp- and the inverter reported the 40 Watt increase accurately, suggesting that the Wattage for the fridge was correct.

 

Iknowwhatcha mean. I limped along an old, slightly undersized, home A/C and after replacing it regretted not just buckling down and doing it sooner.

Another person who has done something similar with his Prius said that once a modern fridge is cold, it maintains coldness well. It's the cooling of a warm or hot cabinet that uses the power.